food allergy blood in stool

The core reason for bloody stools caused by food allergy is that allergenic substances trigger immune and inflammatory reactions in the intestinal mucosa, resulting in micro-damage and oozing of blood on the surface of the intestinal wall. In most cases, as long as you stop ingesting the allergenic food in time, it will resolve on its own in 1-3 days. Only a few serious cases require intervention with anti-allergic and mucosal protective drugs. There is no need to panic excessively, nor can you let it go.

The mother of the 3-year-old boy I met a while ago fed him a whole mango with the skin on for the first time. When he pooped that afternoon, there were several wisps of bright red blood mixed in his diaper. The baby would rub his belly from time to time and complain of bloating. At first, the elders at home thought it was an anal fissure. After struggling for half a night and applying diaper cream, it didn't work. Later, the stool test showed no white blood cells and ruled out bacterial infection. The doctor asked me to stop all the newly added foods. The baby's stool returned to normal the next day. Later, an allergen screening showed that she was moderately sensitive to mango protein.

In fact, our intestinal mucosa is like a layer of fine protective plastic wrap attached to the intestinal wall. Under normal circumstances, only small molecules of digested nutrients are released. When encountering "strange invaders" that have never been seen before - for example, some people are casein in milk, some are allergic proteins to peanuts, and some are even allergic to mangoes and seafood. When it comes to gluten intolerance in wheat, the immune system directly sounds the alarm, and the released inflammatory factors will burn out small holes the size of needle tips in this membrane. In addition, the intestinal peristalsis speed is much faster than usual in the allergic state. The blood seeping from these small holes is mixed with the feces and is excreted, which is what we see as blood in the stool. It should also be mentioned here that the appearance of blood in the stool is directly related to the location of the damage. If the mucosa of the small intestine is damaged, the blood will be mixed with the stool and the stool will be discharged as dark red blood streaks. ； If the area near the rectum or anus is damaged, most of the blood will be attached to the surface of the stool, or even only on the paper when wiping the buttocks. Many people will mistake this situation for hemorrhoids, and even applying ointment for a long time will not improve it.

Regarding the follow-up intervention for this type of allergic blood in the stool, there are actually two completely different ideas in clinical practice. No one is right or wrong, but the applicable groups are different. Most conservative doctors recommend completely avoiding allergenic foods, especially for young babies whose intestinal barrier is not yet fully developed. They should completely avoid allergens for 3-6 months to give the mucous membrane enough time to repair, and then try a small amount after the immune status is stable. Most pediatricians currently use this method. I have a friend's baby with a cow's milk protein allergy who drank deeply hydrolyzed milk powder for half a year and now has no reaction to ordinary pure milk. However, many allergists prefer the idea of ​​gradually inducing tolerance, especially for adults who have passed the critical period of intestinal development. As long as they do not suffer from severe immediate allergies such as laryngeal edema and shock after eating, but only blood in the stool or skin rash, small doses, Exposure to allergens step by step will slowly allow the immune system to "familiar" with the substance and no longer overreact. For example, people with mild allergies to wheat may first eat steamed buns made of millet flour mixed with 1/10 wheat flour, and add a little amount every week. Many people can eat pasta normally after half a year.

Don't tell me, I met a 26-year-old girl before who had blood in her stool every time she ate crayfish. At first, she thought it was because of spicy food that caused hemorrhoids. She applied hemorrhoid ointment for half a month but it didn't work. She also did a gastrointestinal endoscopy and found no ulcers or polyps. Finally, I looked through her food diary and found that she ate crayfish before every time she had blood in her stool. After doing an allergen test, I found out that she was allergic to crayfish tropomyosin. After she stopped eating, she never had any bleeding again. In fact, many people confuse blood in the stool caused by allergies with common gastroenteritis and hemorrhoids. To make a simple distinction, blood in the stool caused by allergies is generally not accompanied by severe abdominal pain or high fever. There are no indicators of bacterial infection in routine stool tests. Most people get better quickly after stopping allergenic foods. ； Gastroenteritis is mostly caused by eating out or eating spoiled food, and is also accompanied by vomiting, diarrhea, and fever. ； The blood from hemorrhoids is usually dripping after defecation, which does not mix with the stool. There will also be anal tingling and swelling. You can make a preliminary judgment first and don't worry about whether you have a malignant disease when you see blood.

Of course, I don’t want you to take it hard. If you still have blood in your stool after stopping the suspected allergenic food for 2 days, or if you have difficulty breathing, wheezes all over your body, or abdominal pain that makes you unable to straighten your back, don’t hesitate to go to the hospital directly. Don’t take hemostatic drugs and antibiotics on your own. If they are not symptomatic, they will put a burden on the intestines. In fact, to put it bluntly, everyone's immune system has a different temperament. The Internet celebrity food that suits others may be your intestinal "assassin". Paying more attention to what you eat will make you feel uncomfortable, which is more effective than taking ten allergen tests. After all, your body is always more honest than the instrument.